Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753048AbaLAKGI (ORCPT ); Mon, 1 Dec 2014 05:06:08 -0500 Received: from cantor2.suse.de ([195.135.220.15]:35475 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753005AbaLAKFy (ORCPT ); Mon, 1 Dec 2014 05:05:54 -0500 Date: Mon, 1 Dec 2014 11:05:47 +0100 From: Jan Kara To: Lino Sanfilippo Cc: eparis@redhat.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, jack@suse.cz Subject: Re: [PATCH 3/3] fanotify: fix inconsistent behaviour regarding flag FAN_ONDIR Message-ID: <20141201100547.GD16185@quack.suse.cz> References: <1417304258-16838-1-git-send-email-LinoSanfilippo@gmx.de> <1417304258-16838-3-git-send-email-LinoSanfilippo@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1417304258-16838-3-git-send-email-LinoSanfilippo@gmx.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun 30-11-14 00:37:38, Lino Sanfilippo wrote: > Before flag FAN_ONDIR was implicitly set in a marks ignored mask. This led to > some inconsistent behaviour: > > 1. It was not possible to remove the flag from the ignored mask, once it was set > (implicitly) with a call like > > fanotify_mark(fd, FAN_MARK_ADD, FAN_OPEN, AT_FDCWD, "dir"); > > This was since the needed flag FAN_MARK_ONDIR was only honored when setting a > marks mask, but not when removing it. Now FAN_ONDIR is only set when explicitly > passed in the masks parameter. It now is also possible to remove it again: > > fanotify_mark(fd, FAN_MARK_ADD, FAN_OPEN | FAN_ONDIR , AT_FDCWD, "dir"); > fanotify_mark(fd, FAN_MARK_REMOVE, FAN_ONDIR , AT_FDCWD, "dir"); > > 2. Subsequent calls to fanotify_mark for a mark that had FAN_ONDIR already set > in its mask removed the flag, if it was not specified in the mask parameter > again. Thus > > fanotify_mark(fd, FAN_MARK_ADD, FAN_OPEN | FAN_ONDIR , AT_FDCWD, "dir"); > fanotify_mark(fd, FAN_MARK_ADD, FAN_CLOSE, AT_FDCWD, "dir"); > > set FAN_ONDIR in the first call on the marks mask but also on the ignored > mask in the second call. So the first request for DIR events was overwritten. > Since the flag is now not set implicitly any longer this cant happen any more. Ugh, I have to say I don't understand the changelog. From the code I think I understood that instead of always adding FAN_ONDIR to ignore mask you require FAN_ONDIR to be set in the normal mask. That makes sense to me but please make the changelog more comprehensible. Also please add a testcase to LTP fanotify() coverage for FAN_ONDIR behavior so that we can easily see how userspace visible behavior changed / didn't change. Thanks! Honza > Signed-off-by: Lino Sanfilippo > --- > fs/notify/fanotify/fanotify.c | 2 +- > fs/notify/fanotify/fanotify_user.c | 24 ++++++++++++++++-------- > 2 files changed, 17 insertions(+), 9 deletions(-) > > diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c > index 30d3add..51ceb81 100644 > --- a/fs/notify/fanotify/fanotify.c > +++ b/fs/notify/fanotify/fanotify.c > @@ -140,7 +140,7 @@ static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark, > } > > if (S_ISDIR(path->dentry->d_inode->i_mode) && > - (marks_ignored_mask & FS_ISDIR)) > + !(marks_mask & FS_ISDIR & ~marks_ignored_mask)) > return false; > > if (event_mask & marks_mask & ~marks_ignored_mask) > diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c > index 3afd8bb..e62463e 100644 > --- a/fs/notify/fanotify/fanotify_user.c > +++ b/fs/notify/fanotify/fanotify_user.c > @@ -493,10 +493,17 @@ static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark, > > spin_lock(&fsn_mark->lock); > if (!(flags & FAN_MARK_IGNORED_MASK)) { > + __u32 tmask = fsn_mark->mask & ~mask; > + if (flags & FAN_MARK_ONDIR) > + tmask &= ~FAN_ONDIR; > + > oldmask = fsn_mark->mask; > - fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask)); > + fsnotify_set_mark_mask_locked(fsn_mark, tmask); > } else { > __u32 tmask = fsn_mark->ignored_mask & ~mask; > + if (flags & FAN_MARK_ONDIR) > + tmask &= ~FAN_ONDIR; > + > fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask); > } > new_mask = fsn_mark->mask; > @@ -573,20 +580,21 @@ static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark, > > spin_lock(&fsn_mark->lock); > if (!(flags & FAN_MARK_IGNORED_MASK)) { > + __u32 tmask = fsn_mark->mask | mask; > + if (flags & FAN_MARK_ONDIR) > + tmask |= FAN_ONDIR; > + > oldmask = fsn_mark->mask; > - fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask)); > + fsnotify_set_mark_mask_locked(fsn_mark, tmask); > } else { > __u32 tmask = fsn_mark->ignored_mask | mask; > + if (flags & FAN_MARK_ONDIR) > + tmask |= FAN_ONDIR; > + > fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask); > if (flags & FAN_MARK_IGNORED_SURV_MODIFY) > fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY; > } > - > - if (!(flags & FAN_MARK_ONDIR)) { > - __u32 tmask = fsn_mark->ignored_mask | FAN_ONDIR; > - fsnotify_set_mark_ignored_mask_locked(fsn_mark, tmask); > - } > - > spin_unlock(&fsn_mark->lock); > > return mask & ~oldmask; > -- > 1.9.1 > -- Jan Kara SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/